Continued advances in our understanding of brain function depend on the presentation of increasingly complex and realistic stimuli. Current stimulus delivery systems are inadequate for this task -- they are expensive, generally DOS-based, and inflexible in the types of stimuli that they can deliver. We have developed an easy-to-use Windows95/98 program, Presentation, that takes advantage of the DirectX gaming functions of Windows to deliver complex stimuli and monitor responses with sub-ms temporal precision. It can deliver auditory, visual or multimodal stimuli and simultaneously monitor responses without special hardware. It incorporates a "TimeVerify (TV)" feature that reports the temporal uncertainties as well as the time of occurrence of all events, assuring a valid timing record under all conditions. In Phase I, we will make further improvements in Presentation including (1) Device drivers to monitor responses using hardware interrupts; (2) Tools to simplify the creation of Presentation-based experiments; (3) A library of ready-to-run examples of classic experiments; and (4) Extensive benchmark testing and documentation of Presentation performance. Throughout, we will work closely with collaborating laboratories expert in fMRI, ERP and behavioral experimentation to optimize Presentation for these demanding applications PROPOSED COMMERCIAL APPLICATION: The proposed activity will lead directly to the production of a commercial software package for the presentation of stimuli in psychology and neuroscience experiments.